Bland, amateurish illustrations and a trite ``be yourself'' theme doom Coplans's ( Spaghetti for Suzy ) second picture book. Dottie, a white dog, is ``always growing things'' (i.e., plants) in the backyard and even in the living room. Her parents try to discourage this un-dog-like behavior, but when Dottie notices other animals behaving against type--Duck roller-skates, Cat sails on the ocean and Rabbit paints pictures--she realizes that it's okay to be different. Her parents finally come around to her way of thinking and, on her birthday, present her with gardening tools; these, oddly enough, are pooh-poohed by Dottie's ostensibly nonconformist peers (`` `A watering can!' said Cat. `You don't need THAT!' . . . . `EVERYONE knows dogs don't grow things,' said Rabbit''). In this way, Coplans's narrative contradicts her message, even though benign smiles on the characters' faces suggest that Dottie has found acceptance regardless. From the uninspired line-drawings and watercolors to the purely simplistic names of every character but Dottie, this story proves stale. Ages 4-8. (Mar.)